System and method for assigning addresses to information handling systems

ABSTRACT

Information handling system network addresses are managed to support a consistent MAC address for iSCSI and fiber channel host bus adapter. For example, a management controller retrieves a MAC address from persistent memory, such as a network location, and assigns the MAC address to a non-persistent memory of a predetermined information handling system network component so that the MAC address remains consistent even if the network component is replaced. For example, an offload engine that supports network communications with iSCSI receives a MAC address from a network location and applies the MAC address for use by a host bus adapter. Alternatively, an offload engine supports Fiber Channel with World Wide Name or World Wide Identifier address assignments.

RELATED APPLICATIONS

The present application claims priority as a continuation-in-part ofU.S. patent application Ser. No. 11/554,090 entitled “System and Methodfor Assigning Addresses to Information Handling Systems,” by CuongNguyen, Michael Brundridge, Bruce Holmes and Michael Roberts, filed onOct. 30, 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to the field of informationhandling system networking, and more particularly to a system and methodfor assigning addresses to information handling systems.

2. Description of the Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Networked information handling systems provide support for many businessand personal applications. Enterprises often network informationhandling systems to use common storage, to enhance communicationsbetween employees and to leverage the use of peripherals, such as commonprinters. Individuals commonly access a variety of networks using modemsor wireless access points to retrieve news, track finances orcommunicate with e-mail and instant messages. Typically, behind eachnetwork is one or more server information handling systems thatcoordinate communication of information between network clients. Largeenterprises will often dedicate rooms that support multiple serverinformation handling systems with specialized cooling and powerequipment. In some instances, multiple servers known as blades operatefrom a common chassis to conserve space while sharing cooling and powerequipment. Large enterprise networks often have a variety of supportorganizations responsible for the deployment and maintenance of networkresources, such as clients, servers, Ethernet local area network (LAN)connections and storage area networks (SANs). In such enterprisenetworks, deployment and maintenance tasks typically are closelycoordinated. For example, if a server information handling system or IOmodule is replaced, MAC and WWN addresses assigned to the replacedsystems have to be updated in a variety of security, deployment andnetworking databases in the LAN and SAN.

A variety of techniques have evolved that attempt to automate addressassignments in response to information handling system server equipmentchanges. One solution uses an external switch to translate MAC addressesassigned to server information handling systems and related devices toexternal MAC addresses used by clients to communicate with theinformation handling system servers and related devices. Essentially, aswitch is placed between the servers and clients so that a mapincorporated with the switch is available to translate the MAC addressesassociated with the servers to MAC addresses used by the network for theservers. This solution supports changes to server information handlingsystems that alter the server MAC addresses by reprogramming the map inthe separate switch so that the replacement MAC addresses map to the MACaddresses used by the network. However, this solution requires aseparate hardware device to support the map, which presents a singlepoint of failure and requires reprogramming with each change to theserver information handling systems.

Similar difficulties arise with networked storage devices, such as iSCSIdevices, which allow clients known as initiators to send SCSI commandsto storage devices on remote servers through Internet Protocol networks.To coordinate network communications, an iSCSI offload engine (iSOE)uses a dedicated MAC address that is different from the local areanetwork (LAN) MAC address. If an iSCSI offload engine has an IPaddressed dynamically assigned by a DHCP server, and the MAC address ofthe Iscsi offload engine changes due to a hardware replacement, thedynamically assigned IP address typically must be manually released andreassigned to the replacement hardware. After reassignment of the IPaddress, switches and routers downstream from the new hardware devicehave to re-learn the MAC address. This process typically takes time andnetwork administrator expertise. In some instances, iSCSI volumes in astorage array are configured such that only a defined IP address orrange of IP addresses can communicate with a give iSCSI volume. If theiSCSI HBA is configured to use DHCP and the MAC address changes, networkadministrators generally must either make changes to the DHCP tomaintain the same IP addresses or change the iSCSI volume configurationto allow the HBA's new IP address to communicate with the volume.

SUMMARY OF THE INVENTION

Therefore a need has arisen for a system and method which maintainsnetwork addresses in the event of changes to hardware of the network.

A further need exists for a system a method which maintains network MACaddresses in a storage network environment.

In accordance with the present invention, a system and method areprovided which substantially reduce the disadvantages and problemsassociated with previous methods and systems for maintaining networkaddresses in the event of changes to hardware of the network. Networkaddresses are stored at a location and assigned to support networkcommunications of information handling systems based on the location ofthe information handling system. A pre-power manager of the informationhandling system retrieves network addresses associated with the locationof the information handling system from persistent memory of thelocation and applies the network addresses to power up networkingcomponents of the information handling system to communicate through thenetwork with the network addresses. MAC addresses are maintainedconsistent at network components, such as iSCSI or FCoE host busadapters, even if an information handling system or network component isreplaced.

More specifically, a blade information handling system chassis hasplural slots, each slot supporting operation of a blade informationhandling system. Persistent storage associated with the chassis storesnetwork addresses for use by blade information handling systems insertedin the slots, such as MAC and WWN addresses. A chassis managementcontroller interfaced with the persistent memory retrieves the addressesand provides the addresses associated with each slot to a baseboardmanagement controller of a blade information handling system inserted ineach slot, such as through a management bus of the chassis. Thebaseboard management controller applies the network addresses associatedwith its slot to power up networking components to communicate with thenetwork addresses. The network addresses applied by the baseboardmanagement controller are not saved to persistent memory so that theaddresses remain associated with the location in the event that theblade information handling system is removed from the slot. In oneembodiment, blade information handling systems removed from the chassisretain the same address by removing the address information from thepersistent memory of the chassis and inserting the address informationin persistent memory of another chassis to support the removed bladeinformation handling system.

The present invention provides a number of important technicaladvantages. One example of an important technical advantage is thatnetwork addresses within a network structure are automaticallymaintained when server information handling systems or related devicesare changed or replaced. Thus, during replacement of server equipmentthe security, network and deployment databases that coordinate operationof the network continue to operate with existing network addresseswithout added external devices, such as a switch having network mapping.By assigning addresses before each boot, server information handlingsystems power up prepared to support communications through traditionalcommunication paths, such as Ethernet. By removing addresses at powerdown, inadvertent duplication of addresses is prevented due replacementof equipment. In one embodiment, assignment of MAC addresses to anoffload engine supports consistent MAC address assignments for use innetwork storage environments, such as iSCSI or FCoE environments.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood, and its numerousobjects, features and advantages made apparent to those skilled in theart by referencing the accompanying drawings. The use of the samereference number throughout the several figures designates a like orsimilar element.

FIG. 1 depicts a block diagram of server information handling systemsconfigured to apply location-based network addresses;

FIG. 2 depicts a block diagram of a blade server information handlingsystem and chassis configured to apply network addresses based on theslot location used to support the information handling system;

FIG. 3 depicts a flow diagram of a process for powering up bladeinformation handling system network components to communicate withaddresses managed by a chassis management controller;

FIG. 4 depicts a flow diagram of a process for replacing a bladeinformation handling system in a blade chassis slot;

FIG. 5 depicts a flow diagram of a process for moving a bladeinformation handling system from a first to a second chassis with thesame network addresses used by the blade information handling system ineach chassis;

FIG. 6 depicts a flow diagram of a process for moving a bladeinformation handling system to a remote location with dynamic addressassignments; and

FIG. 7 depicts a block diagram of a system for maintaining a consistentMAC address with a host bus adapter and offload engine.

DETAILED DESCRIPTION

Associating network addresses to a location for use by an informationhandling system reduces complexities associated with replacing andmoving information handling systems. For purposes of this disclosure, aninformation handling system may include any instrumentality or aggregateof instrumentalities operable to compute, classify, process, transmit,receive, retrieve, originate, switch, store, display, manifest, detect,record, reproduce, handle, or utilize any form of information,intelligence, or data for business, scientific, control, or otherpurposes. For example, an information handling system may be a personalcomputer, a network storage device, or any other suitable device and mayvary in size, shape, performance, functionality, and price. Theinformation handling system may include random access memory (RAM), oneor more processing resources such as a central processing unit (CPU) orhardware or software control logic, ROM, and/or other types ofnonvolatile memory. Additional components of the information handlingsystem may include one or more disk drives, one or more network portsfor communicating with external devices as well as various input andoutput (I/O) devices, such as a keyboard, a mouse, and a video display.The information handling system may also include one or more busesoperable to transmit communications between the various hardwarecomponents.

Referring now to FIG. 1, a block diagram depicts server informationhandling systems 10 configured to apply location-based networkaddresses. Server information handling systems 10 have plural processingcomponents that cooperate to process information, such as a CPU 12, RAM14, a hard disk drive 16, network interface cards 18 and a chipset 20.Plural network interface cards 18 coordinate the communication ofinformation with a network 22, such as a local area network or a storagearea network. A management bus 24, such as an I2C bus or SMBus, supportscommunication of management information through pre-power manager 26.For example, pre-power manager 26 operates with most processingcomponents in a powered down state to support remote power-up,power-down and maintenance of server information handling systems 10through management bus 24. An address manager 28 interfaces withpre-power manager 26 through management bus 24 in order to apply networkaddresses retrieved from local address storage 30. Local address storage30 resides in persistent memory associated with a location, such as aphysical spot in a server room or multi-server chassis. Each specificlocation has associated network addresses that are retrieved for use byinformation handling systems placed at the associated location. Addressmanager 28 provides the network addresses, such as MAC and WWNaddresses, to pre-power manager 26 so that the addresses are availablefor networking components, such as NICs 18, at power up of thecomponents. Pre-power manager 26 applies the network addresses at powerup of the networking components so that network communications aresupported with the network addresses retrieved from location addressstorage 30. Pre-power manager 26 applies the network addresses so that,if the information handling system is subsequently moved then theaddresses will not remain on the information handling system. Forexample, the network addresses are stored in non-persistent memory ofinformation handling system 10.

Referring now to FIG. 2, a block diagram depicts a blade serverinformation handling system 10 and a blade server chassis 32 configuredto apply network addresses based on the slot location used to supportthe blade information handling system 10. Blade server chassis 32 hasplural slots 34 each of which accept a blade information handlingsystem. Blade server chassis 32 has a chassis management controller 36that manages the operation of blade information handling systems 10 inslots 34 through a management bus 24. A management controller 38, suchas a baseboard management controller (BMC) or integrated managementcontroller (IMC), in each blade information handling system 10communicates with chassis management controller 36 to manage operationssuch as powering up and powering down blade information handling system10. With chassis management controller 36 and management controller 38powered up and blade information handling system powered down, networkaddresses, such as MAC and WWN addresses, associated with a slot 34 areretrieved from address EEPROM 30 to enable configuration of networkcomponents, such as a NIC, LOM, and FC HBA 40, before power is appliedto the network components. An IOM 41 located on chassis 32 also includesan Ethernet controller having a MAC address supported by informationstored in EEPROM 30.

After the network addresses are available to the networking componentsfor establishing network communication, chassis management controller 36authorizes management controller 38 to power up blade informationhandling system 10 configured to communicate over network 22. Thenetwork addresses are stored in address EEPROM 30 in a number of ways.In one embodiment, address EEPROM 30 has unique MAC and WWN addressesregistered with appropriate authorities and stored at manufacture ofblade server chassis 32. In an alternative embodiment, a networkmanagement server 42 dynamically assigns network addresses with anetwork address manager 44 selecting from available addresses of anetwork address database 46. Chassis management controller 36 requestsnetwork addresses during its boot, such as by extending the DHCPprotocol so that the MAC and WWN addresses are requested along with anIP address. Network addresses retrieved from network management server42 may be stored in persistent memory of blade server chassis 32 forsubsequent use.

Referring now to FIG. 3, a flow diagram depicts a process for poweringup blade information handling system network components to communicatewith addresses managed by a chassis management controller. At step 48,the chassis management controller starts. At step 50, the chassismanagement controller retrieves a pool of “soft” MAC and WWN addressesfrom the blade chassis persistent memory. At step 52, the chassismanagement controller boots from a DHCP server to establish networkcommunication for the blade server chassis. In addition to retrieving anIP address, the chassis management controller may retrieve MAC and WWNaddresses as a modification to the DHCP protocol. At step 54, thechassis management controller allows assignment of MAC and WWN addressesto blade or IOM locations of the blade server chassis. Alternatively,the DHCP server may send chassis slot assignment information. At step56, the chassis management controller brings up the IOMs and blades andprovides the allocated MAC and WWN addresses to each module. At step 58,the IOMs and blades boot and program the network interfaces with theallocated MAC and WWN addresses.

Referring now to FIG. 4, a flow diagram depicts a process for replacinga blade information handling system in a blade chassis slot. The processbegins at step 60 with a decision to replace a blade informationhandling system. At step 62, the blade information handling system ispowered down and unplugged from the blade server chassis. At step 64,the blade information handling system is physically removed from itsslot in the chassis, although the soft MAC and WWN addresses assigned tothe blade are not retained in the blade but rather retained in thechassis. At step 66, the new blade information handling system isplugged into the chassis slot of the removed blade information handlingsystem. At step 68, the new blade information handling system powers upand the chassis management controller assigns the MAC and WWN addressesassociated with the slot and formerly used by the removed blade to thereplacement blade information handling system. At step 70, thereplacement blade information handling system applies the same MAC andWWN addresses as the removed blade so that the LAN or SAN detects nodifference in hardware.

Referring now to FIG. 5, a flow diagram depicts a process for moving ablade information handling system from a first to a second chassis withthe same network addresses used by the blade information handling systemin each chassis. The process starts at step 72 with a determination tomove a blade information handling system from a first to a secondchassis. At step 74, the blade information handling system is removedfrom the first chassis. At step 76 the soft MAC and WWN addressesassociated with the blade information handling system are deleted fromthe first chassis. At step 78, the soft MAC and WWN addresses are addedto the second chassis and, at step 80, associated with an empty slot inwhich the blade information handling system is to be inserted. At step82, the blade information handling system is plugged into the selectedchassis slot and powered up so that the MAC and WWN addresses previouslyused by the blade in the first chassis are once again used by the bladein the second chassis.

Referring now to FIG. 6, a flow diagram depicts a process for moving ablade information handling system to a remote location with dynamicaddress assignments. At step 84 a determination is made to move a bladefrom a first to a second chassis. At step 86, the soft MAC and WWNaddresses associated with the blade are deleted from assignment to thefirst chassis at the DHCP server. At step 88, the soft MAC and WWNaddresses associated with the blade are added to the assignments of thesecond chassis at the DHCP server. At step 90, the DHCP server is forcedto renew the address information at the first and second chassis. Atstep 92, the chassis management controllers of the first and secondchassis renew the addresses and pick up the new list of soft MAC and WWNaddresses from the DHCP server. At step 94, the chassis managementcontroller in the first chassis sees that the soft MAC and WWN addressesfor a blade are removed. At step 96, the chassis management controllerof the first chassis down the blade that lacks valid MAC and WWN addressinformation. At step 98, the chassis management controller of the secondchassis sees the new soft MAC and WWN addresses assigned to the blade.At step 100, the chassis management controller in the second chassisassigns the new MAC and WWN addresses to the blade information handlingsystem and reboots the blade to apply the addresses.

Referring now to FIG. 7, a block diagram depicts a system formaintaining a consistent MAC address with a host bus adapter 40 andoffload engine 102. Host bus adapter 40 and offload engine 102 providesupport for storage area networks that store information using Internetprotocol techniques, such as an iSCSI storage area network 104 or afiber channel over Ethernet network 106. Client information handlingsystems 10 access storage area networks through host server informationhandling systems 10, which act as initiators to iSCSI targets 110 andfiber channel targets 112. Communications between client informationhandling systems 10, host server information handling systems 10, andtargets 110 and 112 pass through a network 22 having a variety ofnetwork devices, such as local area network switch 108 and a storageswitch 114. Host bus adapters 40 promote use of Internet Protocolcommunications by presenting storage devices as network devices using aMAC address 116 assigned by offload engine 102. Offload engine 102operates as firmware instructions running on host bus adapter 40 or,alternatively, operates independently to assign a virtual MAC address116 to a network interface card 18 which performs host bus adapterfunctions under instructions run on CPU 12 or firmware run on chipset20. A fiber channel host bus adapter 40 has multiple World Wide Name(WWN) addresses, also known as World Wide Identifiers (WWID), assignedfor each port by offload engine 102 to support Ethernet-to-fiber channelfunction 118.

In order to maintain consistent MAC addresses for host bus adapters 40and offload engines 102, a management controller 38 associated with ahost server information handling system 10 retrieves a MAC address frompersistent memory and applies the MAC address to non-persistent memoryfor use by host bus adapter 40 and/or offload engine 102. For example,management controller 38 runs as firmware on chipset 20 or otherprocessing components associated with an information handling system 10having networking components with assignable MAC addresses, such asfirmware on a baseboard management controller. In the embodimentdepicted by FIG. 7, management controller 38 retrieves MAC addressesfrom a network address manager 44 and network address database 46 of anetwork management server 42 and applies the MAC address to apredetermined network component, such as an offload engine 102 or hostbus adapter 40. As is discussed above in greater detail, the MAC addressassigned to the network component is maintained consistent even if thenetwork component or information handling system 10 having the networkcomponent is replaced. For example, MAC addresses are provided fromnetwork management server 42 based on the position of an informationhandling system 10 within a chassis, such as a blade slot location in ablade chassis. Thus, for example, if a blade information handling systemconfigured to support iSCSI with an offload engine 102 is replaced witha replacement blade information handling system, the MAC address of thereplacement blade information handling system offload engine 102 is thesame as the MAC address of the system that was replaced. Similarly, if ahost bus adapter 40 is replaced in an information handling system 10,the configuration of the information handling system to interact withiSCSI storage area network 104 remains unchanged because the same MACaddress is assigned to the replacement host bus adapter 40 as was usedby the replaced host bus adapter 40.

WWN addresses associated with a fiber channel host bus adapter 40 arealso maintained consistent by assigning the WWN address to the fiberchannel host bus adapter 40 from the pool of WWN addresses maintained innetwork management server 42. Fiber channel over Ethernet uses burnt-inWWN addresses during the FIP phase of communication, however, as part ofFIP discovery and login, a new mapped WWN address is configured, such asa WWN address provided from network management server 42 throughout-of-band communication with management controller 38. The mapped WWNaddress is used by a FCoE end node 112 during data transfers. During theFIP phase, end node target 112 and FCoE storage switches agree on theWWN address. An FCoE forwarder function in the FCoE switch chooses anSPMA method with burnt-in WWN addresses that support a flexible WWNaddress or FPMA. Multiple WWN addresses may be burnt in to support FCoEfunctions and LAN functions. In both iSCSI and FCoE environments, a poolof available MAC or WWN addresses are maintained in persistent memoryfor assignment to predetermined network components at power up of thecomponents, with the network components storing assigned MAC addressesin non-persistent memory so that multiple instances of a MAC address donot occur when a network component is replaced.

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade hereto without departing from the spirit and scope of the inventionas defined by the appended claims.

1. An information handling system comprising: a processor operable toprocess information; a network component interfaced with the processorand operable to communicate information with a network using a MediaAccess Control (MAC) address; a management controller in communicationwith the processor, the management controller operable to interface withan address manager to retrieve a MAC address associated with the networkcomponent and to apply the MAC address to the network component forcommunication of information through the network, wherein the MACaddress is stored in persistent memory on the network component; whereinthe management controller is further operable to delete the MAC addressfrom the persistent memory on network component at power down of thenetwork component.
 2. The information handling system of claim 1 whereinthe network component comprises a network interface card.
 3. Theinformation handling system of claim 1 wherein the network componentcomprises a storage area network.
 4. The information handling system ofclaim 1 wherein the management controller comprises firmware running ona chipset.
 5. The information handling system of claim 4 wherein themanagement controller comprises a baseboard management controller. 6.The information handling system of claim 5 further comprising:persistent memory associated with the network component and operable tostore the MAC address; wherein the management controller is furtheroperable to retrieve the MAC address from the persistent memory and toapply the MAC address to the network component.
 7. The informationhandling system of claim 1 wherein the management controller is furtheroperable to retrieve plural MAC addresses for use by the networkcomponent.
 8. A method for managing network Media Access Control (MAC)addresses associated with information handling system networkcomponents, the method comprising: storing network MAC addresses inpersistent memory accessible by the information handling systems;retrieving with a management controller one or more of the network MACaddresses associated with a predetermined network component; applyingthe network MAC address to the predetermined network component, whereinthe MAC address is stored in persistent memory on the predeterminednetwork component; powering up the network component to establishnetwork communications with the network MAC address; and deleting theMAC address from the persistent memory on the predetermined networkcomponent at power down of the predetermined network component.
 9. Themethod of claim 8 wherein applying the network MAC address furthercomprises applying the network MAC address with non-persistent memory sothat the network MAC address is deleted at power down of the informationhandling system.
 10. The method of claim 8 wherein the network componentcomprises a host bus adapter.
 11. The method of claim 8 wherein the hostbus adapter comprises an iSCSI host bus adapter.
 12. The method of claim8 further comprising: removing the predetermined network component fromthe information handling system; inserting a replacement networkcomponent in the place of the removed predetermined network component;and powering up the replacement network component to operate with theone or more network addresses associated with the removed predeterminednetwork component.
 13. The method of claim 8 wherein the networkcomponent comprises an iSCSI offload engine that assigns a networkaddress to a network interface card.
 14. The method of claim 8 whereinthe network MAC addresses comprise plural MAC addresses.
 15. The methodof claim 8 wherein the network component comprises an iSCSI host busadpater.
 16. A system for assigning network addresses to an informationhandling system network component, the system comprising: a managementcontroller operable to retrieve a Media Access Control (MAC) addressassociated with the network component and assign the MAC address to thenetwork component; and a network component interfaced with themanagement controller and operable to apply the MAC address provided bythe management controller, wherein the MAC address is stored inpersistent memory on the network component for communication through anetwork and to delete the MAC address from the persistent memory on thenetwork component at power down of the network component.
 17. The systemof claim 16 wherein the network component comprises an offload engine,the offload engine operable to assign the MAC address to a host busadapter.
 18. The system of claim 16 wherein the network componentcomprises an iSCSI host bus adapter.
 19. The system of claim 16 whereinthe network component comprises a fibre channel host bus adapter and thenetwork address comprises a World Wide Name address.